Computing gun sight



Oct 14, 1947- A. ESSEX COMPUTING GUN SIGHT Filed April 15, 1944 5 Sheets-Sheefc l nvvENToR Alols Essex .fm1/f' ATTORNEY .HNI

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Oct. 14, 1947.

A. ESSEX COMPUTING GUN SIGHT 5 snets-sheet 2 Filed April 15, 1944 )NvENToR AlosEsse ATTORNEY Oct. 14, 1947. ESSEX COMPUTING GUN SIGHT 5 Sheets-Sheet 5 Filed April l5, 1944 n i A d mm lll-lillll I mvENToR Msff/ T M M ATTORNEY oct 14, 1947. A. Essgx 2,428,870

CQMPUTING GUN SIGHT V Filed April 15, 1944 5 Sheets-Sheet 4 :m nuurl'fll 'mmm A. ESSEX COMPUTING GUN SIGHTl Oct. 14, 1947.`

IN VEN TUR AloisEe A TTORNEY Patented Cet. 14, 1947 2.428.870 COMPUTING GUN SIGHT -Alois Essex, Glendale, N. Y., assigner to Ford Instrument Company, Inc., N. Y., a corporation of New Long Island City, York Application April 15, 1944, 'serial Na. 531,272

(ci. zas-.615)

14 Claims. 1

This invention relates to computing sights for.

land based lightartillery such as anti-aircraft or anti-tank'guns, and has for an'object to provide an improved mechanism for automatically computing the reiiection in. train and in elevation and setting this denection into thesight.

In accordance with the present invention the movmentin train measured in the horizontal plane is converted to movements in train and rate of train in the slant plane which rate is combined with a range setting to compute and set the proper deflection into the sight. The rates are measured by magnetic drag devices having rotors driven at speeds proportional to the respective rates of train and elevation to develop torques which cause deflection of spring biased shafts carrying mirrors forming a part of the optical system. The effects of the springs are varied in accordance with range so that the deflections are functions of the respective rates and of range. Provision is also made to compensate for drift and to introduce superelevation which are functions of range. y

The mechanism for converting train movement in the horizontal plane into train movement in the slant plane includes a differential having one input element driven by train movement in the horizontal plane (Bg) and having a second input element driven by the train movementin the horizontal plane (Bg) modified by a function of elevation (Eg) represented by the formula (cos Eg-l) so that the output of the differential represents Bg+Bg cos Eg-l) which is the formula for train movement in the slant plane.

Although the .novel features which are characteristic ofl this invention are pointed out more fully in .the claims the nature of the invention will be better understood by referring to the following. description taken in connection with the accompanying drawings in which certain specic embodiments have been set forth for purpose of illustration.

In the drawings:

Fig. 1 is an elevation of light artillery piece showing the present sight and computing mechanism connected thereto;

Fig. 2 is a diagrammatic view of the computing mechanisms;

Fig. 3 is a diagrammatic viewof a computing mechanism illustrating a further embodiment of V the invention;

Fig. 4 is a detail view of the mirror and control mechanism therefor of Fig. 3;

Fig. 5 is an end elevation of the elevation range yoke, and super-elevation computing mechanisms of Fig. 2;

Fig. 6 is a horizontal section taken along the lines 6-6 of Fig. 2 showing the train range yoke and drift cam;

Fig. 7 is a transverse section taken along the lines 1 1 of Fig. lease clutch;

Fig. 8 is a side release clutch;

Fig. 9 is an enlarged end elevation of the range finder shown in Fig. 3;

Fig. 10 is a side elevation thereof; and

Fig. 11 is a section taken on the lines II-II of Fig. 9.

Referring to the drawings more in detail, the invention is shown in Fig. 1 as applied to a gun I mounted for movement in elevation on trunnions 2 supported in pedestal 3. The pedestal 3 is mounted on a track 4 formovement in train on a stationary base E carrying a gear 8. A box I 0 containing the computing mechanism and carrying a sighting glass II is mounted for movement with the gun I.

Movement in train is fed into the computing mechanism inthe box by means of a pinion I2 carried on a bracket I3 attached to the pedestal 3 and meshing with the stationary gear 6. The pinion I2 is connected by a flexible shaft I4 to the train input shaft I5 of the computing mechanism.

Movement in elevation is fed into the computing mechanism by a pinion I6 engaging an eleeievation of the centrifugal vation segment I1 'mounted on the pedestal 3.

The pinion I 6 drives a flexible shaft I8 which drives the elevation shaft I9 of the computer.

Referring to Fig. 2, the train shaft I5 is shown as carrying a worm 2l and a spur gear 22 and as driving one side of a differential 23. The worin 2| drives a Worm gear 24 carrying or having associated therewith a train dial 25 which indicates the position in train of the pedestal.

'Il'he second input of the differential 23 is driven through bevel gears 26 from a roller 21 which is driven by balls 28 from a disc 29 mounted on a gear 30 meshing with the gear 22. The balls 28 are mounted in a ball carriage 3|, the position of which is controlled by a link 32 actuated by a cam slot 33 formed on a, disc 34, the arrangement being such that the rotation of the roller 21 is dependent upon both the rotation of the disc 29 and the radial position of the balls 28 with respect to said disc.

The disc 34 constitutes an elevation disc which 2 showing the centrifugal re-` represents the elevation `mounted in the frame 69.

is driven by teeth 36 meshing with a pinion 31, the latter being driven through a gear train including beveled gears 38, shaft 39, beveled gears 40, shaft 4I and beveled gears 42 from the elevation shaft I9. The position of the disc 34 thus ofv the gun (Eg). The cam slot 33 on the elevation to impart a movement to the link 32 represented by the formula (cos Eg-1).

The output of the differential 23 drives a shaft 45 which carries a centrifugal clutch 46, shown more in details in Figs. '1 and 8. The clutch 46 comprises a carrier 50 attached to a driven shaft 6I and carrying pivoted arms 52 having weights 53 and held inwardly by springs 54, The arms 52 carry friction members 55 which engage a drum 56 mounted on the shaft 45, the arrangement being such that the shaft is normally driven through-the frictionengag'ement of the members 55 with the drum 56, but is released due to the centrifugal force of the weights 53 when a predetermined speed is exceeded.

The shaft 5I drives the outer element of a magnetic drag 60 of the type which develops a torque in a rotor or inner element proportional'to the speed of rotation of the outer element. If a magnetic drag of this type is driven at too high a speed it looses its magnetism. The centrifugal clutch 46 is designed to prevent this predetermined speed from being exceeded. The rotor of the magnetic drag is connected to a deflection shaft 62 carrying a mirror 63 which forms a part of the optical system and is inclined to the axis of rotation of the shaft 62 for the purpose to be described.

The rotation of the shaft 62 in response to the torque developed by the magnetic drag is controlled by a at spring 65 which is attached to the shaft 62. The effective length of the spring 65 is controlled by the distance of a clip or sliding block 59 from the shaft 62. The block 59 is guided by a slot 51 in a plate 58 forming part of frame 69. A pin 66 extending from the block 59 extends into a cam slot 61 formed in a slide 68 The frame 69 is loosely journalled on the shaft 62 by means of brackets 10. The clip or block 59 extends around the spring 65 and its distance from shaft 62 is controlled by the cam slot 61 in the slide 68.

The slide 68 carries a downwardly extending bracket 1| having a transverse arm 12 (Fig. 6) which is adapted to slide transversely in a slot 13 formed in a slide 14. The slide 14 is provided with a rack 15 driven by a pinion 16 carried on a shaft 11 which is positioned through bevel gears 18 from a range shaft 19 having suitable range setting means shown as a manual handle 80. The slide 14 is mounted by suitable means, not shown, for sliding movement in a longitudinal direction in response to operation of the range shaft, and is shown as provided with a range scale.

The frame 69 also carries an arm 85 having on its end a pin 86 which engages a cam slot 81 (Fig. 6) formed in the slide 14. The cam slot 81 causes the frame 69, to swing about the shaft 62 and is shaped to introduce a movement corresponding to the drift at the various ranges.

The elevation shaft I9 carries a Worm 90 driving a worm gear 9| having attached thereto or associated therewith an elevation dial to indicate the position of the gun in elevation. The elevation shaft I9 also drives, through bevel gears 92, shaft 93 and bevel gears 94, a shaft 95 driving a. shaft 91 through a centrifugal clutch 96,

disc 34 is designed 4 similar to the clutch 46 above described. The shaft 91 drives the outer element of a magnetic drag device 98 which is similar to the magnetic drag device 60 and is adapted .to produce a torque on the inner element dependent upon the speed of rotation of the outer element. The magnetic drag device operates a deection shaft 99 which, through beveled gears |00 controls the angular position of a mirror I0| forming part of the optical system.

The rotation of the shaft 99 in response to a given torque is controlled by a fiat spring |05 attached to the shaft 99. The effective length of the spring |05 is controlled by the distance of a sliding block |04 from the shaft 99. The block |04 is guidedby a slot |02 in a plate |03 forming part of a frame |09. A pin |06 extending from the block |04 extends into a cam slot |01 formed in a slide |08 mounted in the frame |09. The frame |09 is loosely journalled on the shaft 99 by brackets III). The block |04 extends around the spring |05 andits distance from shaft 99 is controlled bythe cam slot |01 in the slide |00.

The slide |08 carries a bracket II2 having an arm I|3 adapted to slide transversely in a slot |I4 formed in a slide II5. 'The slide II5 is provided with a rack II6 meshing with a pinion I I1 carried by a shaft |I8 which is driven through bevel gears ||9 from the range shaft 19.

The frame |09 is swung about the shaft 99 to introduce a vertical deflection corresponding to super-elevation by means of a segmental gear |25 (Fig. 5) driven by a Worm |26 mounted on a shaft |21 having a pinion |28 driven by a rack |29 (Figs. 2 and 5) on an L-shaped arm |30. The arm |30 is provided with a slot |3| receiving a pin |32 which is adjustable in a radial slot |34 in a super-elevation disc |33.

The disc |33 is driven by a pinion |50 and bevel gear |5| from a shaft |52 driven through bevel gears |53 from the elevation shaft I9. y

The pin is adjusted radially in the slot `|34 by means of a disc |45 having a spiral groove |46 which engages said pin. The disc |45 is driven through a gear train including pinion |35, bevel gears |36, shaft |31, bevel and bevel gears |40 from the housing of a differ; ential I4I, one side of which is connected to the range shaft 19. The disc |45 is also turned with the disc |33 from the elevation shaft I9 by means of a shaft |55 connected to the second side of the differential I4I and having a bevel gear |56 meshing with a bevel gear |51 on the shaft |52.

The optical system comprises a collimator |60 having a light source |6I and a lens system |62, which projects rays upon the mirror 63. The mirror 63 is mounted to reflect these rays onto the mirror |0| which reiiects the rays onto sighting glass II which is partially silvered to reflect light rays received from mirror |0I, but is sufiiciently transparent to permit the target T to be viewed therethrough,

In the-operation of this form of the invention, the range, which is determined in any desired manner as by means of a range finder, is manually set into the shaft 19 by means of the handle 80. The gun is then moved in train and in elevation to bring the target T into the center of the light spot formed by the light rays projected onto the sighting glass II by the collimator |60. This movement in train and in elevation operates the train shaft I5 and the elevation shaft I9 respectively which set the corresponding values into the computing mechanism. Movement of the train shaft l5 drives the magnetic device 60 5 through the differential 23 and the centrifugal clutch 46 and thereby produces a torque which causes a rotational movementof the shaft 62 proportional to the rate of movement of the train shaft I5 or to the rate of train of the gun in the horizontal plane (dBg).

If, in addition, the gun is elevated above or 'below the horizontal plane by an amount Eg supplemental movement is vintroduced'into the shaft 45 by the roller 21 and differential 23 as follows: AsA elevation disc 34 is driven by the elevation shaft |9 by an amount representing Eg,

the cam slot 33 causes a movement of the ball carriage 3| to a position representing (cos Eg-l). Inasmuch as the disc 29 is actuated by the train shaft I5, the movement o1 this disc corresponds to movement in train (Bg) of the gun and the movements transferred through theballs 2B to` the roller 21 represents Bg(cos Eg-l). This movement of the roller 21 is combined -by the differential 23 with the movement of the shaft I5 corresponding to Bg so that the resultant movement of shaft 45 represents Bg-l-Bgos Eg-1) and the rate of movement of shaft 45 corresponds to the rate of train movement of the gun in the slant plane (dBs). The torque applied to the shaft 62 accordingly corresponds to dBs.

The rotation of the shaft 62 produced by this torque is controlled in accordance with the time of flight by varying the effective length of the spring 65 as follows. Longitudinal movement of the slide 14 caused by movement of the range shaft 19 shifts the slide 60 along the frame 69. The cam slot 61 thus shifts pin 66 and the block 59 along the spring 65 to vary its effective length.

' The cam slot 61 is designed to modify the action of the spring 65 so that the resultant rotational position taken by the shaft'62 represents the computed deflection in train in the slant plane (TdBs).

Drift which is also a function of range, is introduced by the cam slot 81 (Fig. 6) of the slide 14 which causes pivotal movement of the frame 69 to shift the position of the spring 63 and thereby modifies the rotational deflection of the shaft 62 to correct for ,drift. Hence, the position taken by th'e shaft 62 represents total computed deflection in the slant plane between the line of sight and the gun. This movement of the shaft 62 and of the mirror 63 shifts the direction of the light rays reflected from the sighting glass |I by a corresponding amount.

'Ihe deflection in elevation is applied by means of the mirror in a similar manner as follows: The elevation movement applied to the elevation shaft I9 is converted by the magnetic drag 98 to a torque on the shaft 99 which is proportional to the rate of elevation movement and represents dE. The time of flight is introduced as in the case of the shaft 62, by movement of the pin |06 along the spring due to cam slot |01 as the slide |08 is shifted by means of the rack I I6 which is driven by the range shaft 19. The arrangement is such that th rotating deflection of the shaft 99 represents TdE.

Super-elevation, which is a function of both' elevation and range is introduced from the disc `|33 which is driven by the elevation shaft I9 through the shaft |52 and pinion |50. The pin |32 is positioned radially of the disc |39 by means of the spiral groove |46 in the disc |45, which is adjusted from the range shaft 19 through the differential I 4|, shafts |39 and |31 and pinion |35. These elements are so designed that movement of the rack I 29 produced by the pin |32 when the slot |34 is parallel to the rack |29 represents the super-elevation, for zero elevation of the gun. As the elevation (Eg) of the gun departs from zero the movement imparted to rack |29 for a given range is decreased in proportion to the cosine of the elevation of the gun (Eg). This movement of the rack |29 drives the shaft |21 and worm |26 Fig. 5 and causes the frame |09 to swing about the shaft 99 to modify the rotational deflection of the shaft 99 so that its resultant position corresponds to the computed deflection in elevation plus the required superelevation.

The shaft 99 YVtilts the mirror I0| and shifts the direction of the light rays reflected from the sighting glass vertically by an amount corresponding to the computed total deflection in elevation.

The shifting of the direction of the light rays reflected from the sighting glass automatically introduces the computed deflection between the gun and the target as the operator maintains the target in the center of the light spot established in his eye by the reflected rays.

In the embodiment shown in Fig. 3, the mechanism is similar to that above described except that a single adjustable mirror is utilized in place of the two mirrors4 63 and |0| of Fig. 2 and that a range finder is incorporated in the collimator.

In this embodiment the elements producing the rotational deflection of the shaft 6'2 representing TdBs are similar to those above described and have been given the same reference characters. Likewise, the elements producing the rotational deflection of the shaft 99 corresponding to TdE are similar to those above described except that the shaft 95 of Fig. 3 is driven by bevel gears |10 directly from the elevation shaft I9. The range shaft 19 of Fig. 3 is driven from the range handie through the shaft |1I, bevel gears |12, shaft |13 and bevel gears |14. The shaft |1I carries the pinion ||1 which actuates the rack |I|i as set forth in connection with Fig. 2.

The super-elevation rack |29of Fig. 3 corresponds to the rack |29 of Fig. 2. This rack |29 'drives a pinion |28 which actuates the worm |26 meshing with a segmental gear |25 attached to the frame |09, to cause the frame to swing about the shaft 99 by an amount suited to introduce the required super-elevation. In the embodiment of Fig. 3 the frame |09 is provided with an arm having an arcuate rack |9| which actuates a pinion |92 carried on a shaft |93 provided with a bevel pinion |94 which meshes with a segment |95 of a bevel gear attached to the frame 69 and causes the frame 69 to swing about the shaft 62 an amount proportional to the movement of the frame |09` The adjustments for drift and super-elevation which are approximately proportional, are thus both taken `from the rack 29.

In Fig. 3 the shaft 62 carries a U-shaped bracket |98 (Fig. 4) to which is pivoted a frame |99 carrying a. mirror 200. The frame |99 carries a pin which slides in a slot-203 in an arcuate bail 204, mounted for pivotal movement about a horizontal axis in brackets 205 and actuated verse axis for deiiecting the projected light rays in elevation.

The range finder mechanism of Fig. 3 is of the steadier type and comprises a sliding plate 201 (Figs. 3, 9, and 11) having a plurality of sets of rings 208 marked therein. The sliding plate 201 is mounted in the collimator |60 in a position to project the light rays from the rings 208 onto the sighting glass Il. The plate 201 may be made ofr non-transparent material having openings therein in which are inserted transparent material on which the rings 208 are marked or the plate 201 may be made of transparent material, in which event the areas surrounding the rings 208 may be rendered nontransparent if desired.

It will be noted that three rings are shown ineach set 208. These rings are of different diameters to be used according to the size of the target, as for sighting on small, medium, or large sized planes.

The plate 201 is mounted on a frame including a slide 209 having a plurality of recesses 2|0 formed therein which are engaged by a pin 2H (Fig. l1). having a rounded or cone shaped end suited to engage and position the slide 209 so that the selected rings 208 register with the collimator. The pin 2li is held in engagement with the'recesses 2l0 by means of a spring 2i2. The slide 209 and plate 201 slide in a suitable channel formed in the collimator |60.

For converting the continuous movement of the shaft IH into step by step movement of the plate 201 there is provided a rack 215 engaging a pinion 2|6 on shaft |1| and carrying a cylinder 2I8 in which a plunger 2I9 is seated'between springs 220 and 22|. Theplunger 2|9 is attached to a rod 222 which ,is secured to the slide 209, the arrangement being such that the springs 220 and 22| hold the plunger 2|9 in a central position of the cylinder 2I8 until the engages one of the recesses 2I0 to position one of the sets of rings 208 in the center of the path of the collimator rays. The slide 209 is held in this position until sufficient force has been built up by compression of one of the springs 220 or 22|, to overcome the holding force of the pin 2li and move the slide 209 until the pin 2li engages the next recess 2|0. Hence, one set of rings 208 is` always presented in the path of the collimator rays.

The operator adjusts the range handle 80 of Fig. 3 until the size of the selected ring which is projected by the collimator onto the sighting glass Il just encompasses the target. The setting of the range shaft I1l then corresponds to the approximate range of the target.

The operation of the system shown in Fig. 3 is similar to that described in Fig. 2 except that the operator, in addition to training and elevating the gun Aso as to keep the target in the center of the light spot formed in his eye by the light rays reflected from the sighting glass Il, actuates the range handle 80 so as to cause the collimator to project on sighting glass Il and thence to his eye, a ring which corresponds in size with the apparent size of the target. This adjustment of the shaft actuates the racks and H8 as described in connection with Fig. 2.

It will be notedl in the above described computing mechanism that movement in train in the horizontal plane is converted automatically into the movement in the slant plane which represents the true rate of train of the target. This latter quantity is used for computing the deflection.

The mechanism is comparatively simple and is especially suited for use with land based light artillery or machine guns.

Although certain specific embodiments of the invention have been set forth for purpose of illustration. it is to be understood that the invention is capable of various adaptations and uses as will be apparent to a person skilled in the art. The invention is only to .be restricted in accordance with thefollowing claims.

I claim:

1. A mechanism for computing the deflection of a line of sight with respect to a gun mounted for movement in train and in elevation, comprisan input driven by said ing a-train shaft driven by movement of said gun in train and an elevation shaft driven by movement of said gun in elevation at rates respectively representing the rate of train (dBg) and the rate of elevation (dE), variable ratio mechanism having an input driven by the movement of said train shaft, having a ratio control member driven by said elevation shaft and having an output shaft driven at a rate representing the rateof train in the slant plane (dBs), a drag device having an input driven by said last shaft and adapted to produce a torque proportional to the rate of movement of said shaft, a spring biased shaft connected to be actuated in response to said torque, and means for varying the spring bias of said last shaft as a function of range so that the deflection of said shaft represents the computed deflection in train.

2. A mechanism for computing the deflection of a line of sight with respect to a gun mounted for movement in train and in elevation, comprising a train shaft driven .by movement of said gun in train and an elevation shaft driven by movement of said gun in elevation at rates respectively representing the rate of train (dBg) and the rate of elevation (dE), variable ratio mechanism having an input driven by the movement of said train shaft, having a ratio control member driven by said elevation shaft and having an output shaft driven at a rate representing therate of train in the slant plane (dBs), a drag device having an input driven by said last shaft and adapted to produce a torque proportional to the rate of movement of said shaft, a spring biased shaft connected to be actuated in response to said torque, means for varying the spring bias of said last shaft as a function of range so that the deflection of said shaft represents the computed deflection in train, and means actuated as a function of range to produce an additional movement in said spring biased shaft to compensate for drift of the projectile.

3. A mechanism for computing the deflection of a line of sight with respect to a gun mounted for movement in train and in elevation, comprising a train shaft driven by movement of said gun in train and an elevation shaft driven by movement of said gun in elevation at rates respectively representing the rate of train (dBg) and the rate of elevation (dE), a differential having train shaft, a variable ratio mechanism having an input driven by said train shaft and a ratio control member driven by said elevation shaft as a function of elevation represented by the formula (cos Eg-l), means connecting the output of said variable ratio mechanism to drive a second input of said differential, a shaft driven by the output of said differential, said last shaft having a rate representing rate of train in the slant plane, a drag device having an input driven by said last shaft and operable to produce a torque proportional to the rate of movement of said last shaft, a device having a spring biased element and means responsive to said torque to deect said element by an amount representing rthe computed deflection.

4. A mechanism for computing the deflection of a line of sight with respect to a gun mounted for movement in train and in elevation, comprising a train shaft driven by movement of said gun in train and an elevation shaft driven by movement of said gun in elevation at rates respectivelygrepresenting the rate of train (dBg) and the rate Vof `elevation (dE), a differential having an input `driven by said train shaft, a variable ratio mechanism having an input driven by said train shaft ,and.a ratio control member driven by said elevation shaft as a function of elevation represented by the formula (cos E`g-1), means condevice including means for adjusting the spring bias in accordance with range.

5. A mechanism for computing the deflection of a line of sight with respect to a gun mounted for movement in train and in elevation, comprising a train shaft driven by movement of said gun in train and an elevation shaft driven by movement of said gun in elevation at rates respectively representing the rates of train (dBg) and the rate of elevation (dE), a differential having an input element driven by said train shaft, a disc driven by said train shaft, a roller parallel to said disc for driving the second input of said differential, adjustable driving means inter-connecting said disc and roller for driving said roller in response to rotation of said disc, cam means driven by said elevation shaft to shift said driving means radially of said disc in accordance with a function of the movement of 4said elevation shaft represented by the formula (cos Eg-1) so that the output of said differential represents Bg--Bgos Eg-1),` ashaft driven 'by the output of said differential, a deflection element, means for displacing said denection element in accordance with the rate of said last shaft, spring means to control the deilection of said last element, and means for varying the effect of the Spring means in accordance with the range, whereby the angular position of said deflection element represents the computed deflection in train.

6. A mechanism for computing the deflection between the line of sight and a gun, comprising a range input shaft and a train input shaft, a deflection element, means responsive to the rate of movement of said train input shaft to apply a torque to said deflection element, means for opposing the torque applied to said deflection element including a spring secured to and extending from said element, an adjustable block positioning the outer end of said spring and means responsive to movement of said range shaft to adjust said block longitudinally of said spring for varying the effective length of the spring whereby the resultant movement of said element due to the applied torque represents a function of the rate 0f train and range and is a measure of the corresponding deflection in train of the line of sight. 7. A mechanism for computing the deflection i between the line of sight and a gun, comprising a range input shaft and a train input shaft, a deflection element, me'an's responsive to the rate of movement of said train input shaft to apply a torque to said deflection element, means for opposing the torque applied to said deflection element including a spring secured to and extending from said element, an adjustable -block positioning the outer end ef said spring, a sliding member having a cam slot engaging a cam follower on said block and adapted to move said block longitudinally of said spring for varying the effective length of said spring, and means responsive to movement of said range shaft for actuating said sliding member. e

8. A`mechanism for computing thedeection between the line of sight and a gun, comprising a range input shaft and a train input shaft, a deflection element, means responsive to the rate of movement of saidtrain input shaft to apply a torque to said deflection element, means for opposing -the torque applied to said deflection element including a spring secured to and extending from said element, an adjustable block positioning the outer end of said spring, a sliding member having a cam slot engaging a cam` follower on said block and adapted to move said block longitudinally of said spring for varying the effective length of said spring, means responsive to movement of said range shaft for actuating said sliding member, a frame carrying said sliding member and pivoted for movement about the axis of said deflection element, and a cam member driven by said range shaft and adapted to swing said frame to modify the position of said deflection element, said last cam member being adapted to swing said frame an amount representing the drift of the projectile corresponding to the setting of the range input shaft. ,e 4

9. A mechanism for computing the deflection between the line of sight and a gun, comprising a range input shaft and a train input shaft, a deflection element, means responsive to the rate of movement of said train input shaft to apply a torque to said deflection element, means for opposing the torque applied to said deflection element including a spring secured to and extending from said element, an adjustable block positioning the outer end of said spring, a frame pivoted for movement about the axis of said deflection element, a slide carried by said frame and movable axially of said deflection element, said slide having a slot engaging said block to adjust the same for varying the effective length of said spring, a rack driven by said range shaft, and means connected to said rack to drive said slide, whereby the angular position of said deection element is a function of both rate of train and range and represents the corresponding deection in train.

10. A mechanism for computing the deflection between the line of sight and a gun, comprising a range input shaft and a train input shaft, a deilection element, means responsive to the rate of movement of said train input shaft to apply a torque to said deflection element, means for opposing the torque applied to said deflection element including a spring secured to and extending from said element, an adjustable block positioning the outer-end of said spring, a frame pivoted for'movement about the axis of said deflection element, a slide carried by said frame and movable axially of said deflection element, said slide having a slot engaging said block to adjust the same for varying. the effective length of said spring, a rack driven by said range shaft, means connected to said rack to drive said slide, whereby the angular position of said-deflection element is a function of both rate of train and range and represents the corresponding deflection in train. and cam means actuated by said rackto modify the angular position of said frame about the axis of said deflection element, said lastcam means introducing a correction representing drift.

11. A mechanism for computing the deflection between the line of sight and a gun, comprising a range input shaft and a train input shaft, a deflection element, means responsive tothe rate of movement 4of said train input shaft to apply a torque to said deflection element, means for opposing the torque applied to said deflection element including a spring secured to and extending from said element, an adjustable block positioning the outer end of said spring, a frame pivoted for movement about the axis of said deflection element, a slide carried by said frame and movable axially of said deflection element, said slide having a slot engaging said block to adjust the same for varying the effective length of said spring, a rack driven by said range shaft, means connected to said rack to'drive said slide, whereby the angular position of said deflection element is a function of both rate of train andrange and represents the corresponding deflection in train, means for shifting said frame to modify the angular position of said deflection element, a mechanism having inputs settable in accordance with elevation and by the range input shaft respectively and having an output representing superelevation, and means for actuating said last means proportionally from said output to introduce a correction representing drift.

12. A mechanism for computing the deflection between the line of sight and a gun mounted for movement in train and in elevation, comprising a train shaft driven by movement of said gun in train and an elevation shaft driven by movement of said gun in elevation atrates respectively representing the rate of train and the rate of elevation, a range shaft to be adjusted in accordance with range, a train deflection element and an elevation deflection element, means for applying torques to said elements proportional to the rates of train and elevation respectively of said train land elevation shafts, means for opposing the torques applied to said elements comprising springs secured to and extending from said'elements respectively, blocks adjustably engaging said springs for controlling the effective length thereof, slides having cam slots engaging follower pins secured to said blocks to shift the blocks longitudinally of said springs, and drive means actuated by said range shaft to control the position of said slides whereby the positions of said deflection elements represent functions of the respective rates and of range.

13. A mechanism for computing the deflection between the line of sight and a gun mounted for movement in train and in elevation, comprising a train shaft driven by movement of said gun in train and an elevation shaft driven by movement of said gun in elevation at rates respectively representing the rateof train and the rate of elevation, a range shaft to be adjusted in accordance with range, a train deflection element and an elevation deflection element, means for applying torques to said elements proportional to the rates of train and elevation respectively of said train ancl elevation shafts, means for opposing the torques applied to said elements comprising springs secured to and extending from said" elements respectively, blocks adjustably engaging said springs for controlling the effective length thereof, slides having cam slots engaging follower pins secured to said blocks to shift the blocks longitudinally of said springs, drive means actuated by said range shaft to control the position of said slides whereby the positions of said deection elements represent functions of the respective rates and of range, frames carrying said slides and mounted for pivotal movement about the axis of the respective deflection members, a mechanism having inputs driven by said elevation shaft and said range` shaft respectively and having an output representing super-elevation, and

vmeans connecting said output to effect pivotal movementl of both of said frames for adjusting lthe elevation deection element in accordance with super-elevation and for adjusting said train deflection element in accordance with drift.

14. A mechanism for computing the deflection between the line of sight and a gun, comprising a range input shaft, a second input shaft representing the angular movement of the gun, a deflection element, means responsive to the rate of movement of the second input shaft to apply a torque to the deflection element, means to oppose the torque applied to the deflection element, and means controlled by the range input shaft to adjust the torque opposing means.

AIDIS ESSEX.

REFERENCES CITED The following references areI of record in the file of this patent: 

